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 #include &lt;qimage.h&gt;
 #include &lt;qcolor.h&gt;

 static inline int blendComponent( int v, int av, int s, int as )
 {
     return as*s + av*v -(av*as*s)/255;
 }

 static inline QRgb blendShade( QRgb v, QRgb s )
 {
     <span class="comment">//</span>shadow image is already reduced and blurred
     int as = qAlpha(s);
     int av = qAlpha(v);
     if ( as == 0 || av == 255 )
         return v;

     int a = as + av -(as*av)/255;

     int r = blendComponent( qRed(v),av, qRed(s), as)/a;
     int g = blendComponent( qGreen(v),av, qGreen(s), as)/a;
     int b = blendComponent( qBlue(v),av, qBlue(s), as)/a;

     return qRgba(r,g,b,a);
 }

 int main( int*, char**)
 {
     QImage image( &quot;out.png&quot; );
     image.convertDepth( 32 );
     QImage shade( &quot;outshade.png&quot; );
     shade.convertDepth( 32 );
     int dx = 10;
     int dy = 5;

     int w = image.width();
     int h = image.height();

     QImage img( w+dx, h+dy, 32 );
     img.setAlphaBuffer( TRUE );

     for ( int y = 0; y &lt; h+dy; y++ ) {
         for ( int x = 0; x &lt; w+dx; x++ ) {
             QRgb sh =  (x&lt;dx||y&lt;dy) ? 0 : shade.pixel( x-dx, y-dy );
             QRgb pixel = (x&lt;w&amp;y&lt;h) ? image.pixel( x, y ) : 0;
             img.setPixel( x, y, blendShade( pixel, sh ) );
         }
     }
     img.save(&quot;blend.png&quot;, &quot;PNG&quot; );
 }</pre>
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